Setra System Model ASM - Manual (Page 3)

3
The current flows into the +EXC terminal and returns back to the power sup-
ply through the -EXC terminal (See Diagram 1). Note: The +SIG Out and -SIG
Out terminals are not used. The power supply must be a DC voltage source
with a voltage range between 9 and 30 VDC measured between the + and
- terminals. The unit is calibrated at the factory with a 24 VDC loop supply
voltage.
3.4 Cable for Bayonet Connectors
For good EMC performance, shielded cable shall be used and grounded to
earth ground. Cable shall only be used within a building and not be longer
than 30 m (100 ft.).
Diagram 1
Electrical Data
Signal Output Ranges 0-5 VDC, 0-10 VDC (4-wire); 4-20mA (2-Wire)
Nominal Excitation 24 VDC
Excitation Range 9-30 VDC (5 VDC & 4-20mA output)
15-30 VDC (10 VDC Output)
Current Consumption <23mA
Circuit Response Time <10ms (Voltage Version),
<80ms (4-20mA Version)
Warm-up, Environmental Within +/-0.02%FS after 15 min. Warm-up Time
Miswiring Reverse Excitation Protection
4.0. CALIBRATION
The ASM transducer is factory calibrated and should require no field adjust-
ment if mounted in a vertical position. Whenever possible, any zero and/or
span offsets should be corrected by software adjustment in the user’s control
system. However, fine zero and span adjustments can be made through use
of Secure-Cal TM accessory (purchased separately) for calibration access. The
Model ASM transducer zero offset is trimmed in the vertical position (pressure
port pointing downward) prior to shipping from factory.
4.1 Zero/Span Adjustments with Secure-Cal TM
To make secure zero and span adjustments, attach SecureCal TM accessory to
ASM pressure transducer. (See Diagram 2).
+
_
9 to 30 VDC
ASM
Current
Monitoring
Device